See also the toplevel.

What custom laptop would be complete without a custom operating system? I'm doing the initial groundwork to build out an operating system, though it's highly dependent on what system board I end up going with. I'd like to write it in Rust, so I'm working through a few OS walkthroughs with Rust. Some initial design notes:

• I'm not really aiming for any sort of POSIX compliance.
• It should be a single user system, which has a number of consequences.
  • The init system just needs to bring up a shell. The first pass at the OS won't have multiple virtual consoles, which will simplify things.
  • I'd like to explore process security mechanisms besides users and groups.
  • What does a single user login look like? How does authentication work?
• I'd like to explore object capabilities [#] as a security mechanism. I've done some explorations with object capability file stores in the past [#], but it's still a topic I'm woefully undereducated in.
• The filesystem is still an open question.
  • The filesystem should be encrypted as a basic security measure. This requires some crypto support in the kernel, which adds more complexity.
  • Which filesystem to use is another question. FAT doesn't provide much extra metadata for files but is easy to implement; ext2 and family aren't too much more complicated, relatively speaking, but I think they're based on users and groups (e.g. the Unix permissions model).
  • How do processes work in this system? How about scheduling?

There's more questions than this, but it's definitely going to be a lot of work. I think I've convinced some smart people to help, so that'll be good. I'll end up doing a lot of reading up on other efforts, like Fuchsia [#], Redox [#], KeyKOS [#], CapROS [#], etc.

After the kernel comes the question of the userspace. I think the roadmap for this is going to end up with multiple stages. The essential software that'll need to be written are an editor (I'd like an mg-like editor at first, but we'll see), some interpreted language (maybe a scheme or forth, but maybe porting Python over), a text-only web browser (or resurrect gopher ;)), a busybox analogue (e.g. all the necessary system tools), and git (or some other SCM [#]). After that comes a PDF viewer, a tmux analogue, an assembler, and a mesh network controller. Finally, a C compiler and/or porting Rust over, maybe adding a GUI/windowing system, and adding things like CSS support to the browser.

I had this crazy backburner idea of something like a system that's part wiki, part activitypub sort of thing that could be used without needing public infrastructure. That's the think-big, think-far, sort of project. This presumes, of course, that this goes anywhere.